1 / 14

MET Performance Studies with Full Simulation

MET Performance Studies with Full Simulation. Shuichi Kunori U. of Maryland 7-June-2000. Issues. MET Resolution MET(x,y) = - ( S Ex(i), S Ey(i)) s (MET) = a/( S Et(i)) 1/2 , ( I: readout channel) Sensitive to pile-up noise / dead channels threshold in readout

tadita
Download Presentation

MET Performance Studies with Full Simulation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. MET Performance Studieswith Full Simulation Shuichi Kunori U. of Maryland 7-June-2000

  2. Issues • MET Resolution • MET(x,y) = -(SEx(i),SEy(i)) • s(MET) = a/(SEt(i))1/2, ( I: readout channel) • Sensitive to • pile-up • noise / dead channels • threshold in readout • LSB (L1: ~1GeV, offline 0.2 GeV) ? • How to improve? • Trigger • How low threshold can we go? • Limited by resolution for QCD events with zero MET.

  3. MET in tH+ Offline MET cut >100GeV (R.Kinnunen)

  4. tH+ : Selection & Signal Assumed Trigger: 3 jets (Et>20GeV) plus tau-jet (Et>100GeV)

  5. Offline MET Response (H->bb)

  6. * 100% sqrt(ScalarET) Average MET (GeV) * * * * 18 GeV for 17.3 min-bias * Scalar Et Offline MET Resolution QCD Jets with no neutrino/muon (no pile-up) Ex = S (Ex-tower) Ey = S (Ey-tower) Any way to improve this? e.g. Ex’=Ex+S ( D(Ex-jet)) Ey’=Ey+S ( D(Ey-jet)) Does this work?

  7. Minimum Bias Event Overlap(in-time only) X-sec = 55mb >>> 17.3 min-bias/crossing at 10E34 Et Flow Scalar Et ( eta<5 ) (particles) ~17 GeV in unit (eta x phi) ! <Scalar Et> = 1080 GeV ( equiv. cone radius 0.56 ) Note: <Scalar Et> = 750 GeV for ttH

  8. MET with Pile-up(eta 5 vs 7) (CMSJET simulation) (S.Abdullin) MET (GeV) gen. cmsjet eta res. all(*) 5 15.49 19.36 21.53 7 5.21 12.92 17.80 (all = res. & B-field & vtx smearing) ~ Equal contribution from eta 5-7, resolution and B-field (15GeV) (12GeV) (9-12GeV)

  9. CMSIM Simulation • HF2: • Z=1613-1628-1748-1778cm • em had tail • Rin= 2.5cm, Rout=130cm • Material: Cu(W) + fibers • Segmentation • eta=0.348, phi=20deg. • Size • 6.1x7.2cm at eta 5 • : • 1.1x0.9cm at eta 7

  10. Rates with Pile-up(ORCA3) No pile-up In-time pile-up Huge rate below MET < 100 GeV due to min-bias at 10E34. (P.Hidas)

  11. MET Threshold for 95% efficiency Different ways to calculate MET Note: H->tau+tau is relatively low jet multiplicity events. (P.Hidas)

  12. RMS 35 GeV 37 GeV 36 GeV > .5 GeV > 1 GeV > 1GeV 42 GeV 44 GeV > 2 GeV > 3 GeV MET for Signal Events with Pile-up and Tower Threshold No min-bias ttH(110) with 17.3 min-bias events GeV Tower = Ecal+Hcal >> Not much pile-up effect with this resolution! >> Resolution gets worse as threshold increase.

  13. MET and LSB tth(110) with 17.3mb LSB 1 GeV 0 GeV

  14. Summary • We just started studies of MET performance at 10E34. We have checked effects due to: • eta coverage and (in-time) pile-up • tower Et threshold / LSB • => Need to check effects due to non-linearity • algorithm for MET scale correction • Is there better way to calculate MET than simply using raw readout channels? • We may need various algorithm depending on final states. --- using Jets, tracks, etc. ??? • Suggest us challenging bench mark physics processes for offline and trigger MET! • HELP!

More Related